| abstract |
An injectable composition is described having a higher residual effect with reduced detrimental effects such as pain at injection site, swelling, tissue irritancy or necrosis. The composition contains as active principle a tetracycline compound, either as the free base or a salt thereof with a physiologically acceptable acid, complexed with a substantially equimolar amount of a magnesium compound, and is solubilized in a water miscible solvent system comprising glycerol formal in a an amount of about 40 (v/v); with from about 1% to about 20% (v/v) polyethylene glycol and optionally containing a pH modifier in an amount sufficient to maintain a physiologically acceptable pH. In addition, the composition may further comprise a thickener, such as polyvinyl in an amount of about 10% (w/v). The balance of the composition comprises water. |